From fb14e1881f0a1da9fe9396c26d9bcdf812994380 Mon Sep 17 00:00:00 2001
From: SarahW <pcem@pcem-emulator.co.uk>
Date: Sat, 24 Mar 2018 19:50:26 +0000
Subject: [PATCH] Moved post-rev1065 0x3da code to OTI-037C specific code.
 Restored pre-rev1065 generic SVGA 0x3da code. Fixes PS/2 VGA self test.

---
 src/vid_oti037.c | 39 +++++++++++++++++++++++++++++++++++++++
 src/vid_svga.c   | 32 --------------------------------
 2 files changed, 39 insertions(+), 32 deletions(-)

diff --git a/src/vid_oti037.c b/src/vid_oti037.c
index 3843c1f..eb06416 100644
--- a/src/vid_oti037.c
+++ b/src/vid_oti037.c
@@ -109,6 +109,45 @@ uint8_t oti037_in(uint16_t addr, void *p)
                 temp = svga->crtc[svga->crtcreg & 31];
                 break;
 
+                case 0x3DA:
+                svga->attrff = 0;
+                
+                /*The OTI-037C BIOS waits for bits 0 and 3 in 0x3da to go low, then reads 0x3da again
+                  and expects the diagnostic bits to equal the current border colour. As I understand
+                  it, the 0x3da active enable status does not include the border time, so this may be
+                  an area where OTI-037C is not entirely VGA compatible.*/
+                svga->cgastat &= ~0x30;
+                /* copy color diagnostic info from the overscan color register */
+                switch (svga->attrregs[0x12] & 0x30)
+                {
+                        case 0x00: /* P0 and P2 */
+                        if (svga->attrregs[0x11] & 0x01)
+                                svga->cgastat |= 0x10;
+                        if (svga->attrregs[0x11] & 0x04)
+                                svga->cgastat |= 0x20;
+                        break;
+                        case 0x10: /* P4 and P5 */
+                        if (svga->attrregs[0x11] & 0x10)
+                                svga->cgastat |= 0x10;
+                        if (svga->attrregs[0x11] & 0x20)
+                                svga->cgastat |= 0x20;
+                        break;
+                        case 0x20: /* P1 and P3 */
+                        if (svga->attrregs[0x11] & 0x02)
+                                svga->cgastat |= 0x10;
+                        if (svga->attrregs[0x11] & 0x08)
+                                svga->cgastat |= 0x20;
+                        break;
+                        case 0x30: /* P6 and P7 */
+                        if (svga->attrregs[0x11] & 0x40)
+                                svga->cgastat |= 0x10;
+                        if (svga->attrregs[0x11] & 0x80)
+                                svga->cgastat |= 0x20;
+                        break;
+                }
+                return svga->cgastat;
+
+
                 case 0x3DE: 
                 temp = oti037->index;
                 break;
diff --git a/src/vid_svga.c b/src/vid_svga.c
index 1de0a20..d94606f 100644
--- a/src/vid_svga.c
+++ b/src/vid_svga.c
@@ -261,43 +261,11 @@ uint8_t svga_in(uint16_t addr, void *p)
                 case 0x3DA:
                 svga->attrff = 0;
 
-                /* old diagnostic code
                 if (svga->cgastat & 0x01)
                         svga->cgastat &= ~0x30;
                 else
                         svga->cgastat ^= 0x30;
                 return svga->cgastat;
-                */
-                svga->cgastat &= ~0x30;
-                /* copy color diagnostic info from the overscan color register */
-                switch (svga->attrregs[0x12] & 0x30)
-                {
-                        case 0x00: /* P0 and P2 */
-                        if (svga->attrregs[0x11] & 0x01)
-                                svga->cgastat |= 0x10;
-                        if (svga->attrregs[0x11] & 0x04)
-                                svga->cgastat |= 0x20;
-                        break;
-                        case 0x10: /* P4 and P5 */
-                        if (svga->attrregs[0x11] & 0x10)
-                                svga->cgastat |= 0x10;
-                        if (svga->attrregs[0x11] & 0x20)
-                                svga->cgastat |= 0x20;
-                        break;
-                        case 0x20: /* P1 and P3 */
-                        if (svga->attrregs[0x11] & 0x02)
-                                svga->cgastat |= 0x10;
-                        if (svga->attrregs[0x11] & 0x08)
-                                svga->cgastat |= 0x20;
-                        break;
-                        case 0x30: /* P6 and P7 */
-                        if (svga->attrregs[0x11] & 0x40)
-                                svga->cgastat |= 0x10;
-                        if (svga->attrregs[0x11] & 0x80)
-                                svga->cgastat |= 0x20;
-                        break;
-                }
-                return svga->cgastat;
         }
 //        printf("Bad EGA read %04X %04X:%04X\n",addr,cs>>4,pc);
         return 0xFF;